Timepiece



April 13, 1965 F. MEYER 77,

' TIMEPIECE Filed Oct. 25, 1965 2 Sheets-Sheet l INVENTOR ATTO R N EY A ril 13,1965 F. MEYER 3,177,647

TIMEPIECE Filed Oct. 25, 1963 2 Sheets-Sheet 2 INVENTOR Friedrich Neger BY ATTO R N EY United States Patent This invention relates to a timepiece comprising a date indicator, advancing means and locking means for the same. In prior timepieces of this type a spring loaded locking member engages the toothing of the date indicator, thereby locking the date indicator in its indicating positions. Relatively high spring forces are required in such prior devices for maintaining the date indicator in its indicating positions, and consequently high turning moments are required for advancing the date indicator.

While such relatively high turning moments for advancing the date indicator are usually available in large-size and spring-driven timepieces, it may prove to be impossible in small-size timepieces and particularly in electric timepieces driven from the balance wheel to advance such a date indicator.

This invention relates to a novel timepiece allowing fast advance of a date indicator by means of relatively small forces. The timepiece according to this invention broadly comprises a toothed date indicator, rotatable advancing means for the date indicator and locking means for the date indicator including a locking wheel rotatable with the same speed as the said advancing means, a substantially cylindrical portion of said locking wheel engaging the toothing of the date indicator with little clearance, the said locking wheel having a recess in its substantially cylindrical portion, the advancing speed of the date indicator and the circumferencial speed of the locking wheel being so adjusted that the date indicator is advanced by one tooth interval while said recess of the locking wheel advances through positions unlocking the date indicator during advance of the latter by one tooth interval.

The said locking wheel usually engages the toothing of the date indicator with little clearance and without friction, but periodically allows an advance of the date indicator without hindering the advancing movementof the date ring when the said recess of the locking wheel enters into the toothing of the date indicator.

It is a particular object of this invention to avoid spring loaded locking members engaging the date indicator or the said locking wheel in order to prevent undesired displacement of these elements by providing means for locking the said locking wheel against rotation in its operating positions.

The attached drawings show, by way of example, one embodiment of the timepiece according to this invention.

FIG. 1 illustrates the mechanism, as far as required for a proper understanding, in a position immediately before advancing,

FIG. 2 advancing,

FIG. 3 is a section along line II-II of FIG. 1,

FIG. 4 shows a part of 'FIG. 1 on an enlarged scale, and

FIG. 5 is a section along line V-V in FIG. 1.

FIGS..1 and 2 illustrate the minute wheel 1 driven from the minute shaft by a pinion 2 at a ratio of 3:1 so that the minute wheel 1 rotates at a speed of one rotation in threehours. The pinion 3 of the minute wheel 1 gears .with the hour'wheel 4. A crank lever 5 with a driving illustrates the mechanism immediately after 'pin 6 is fixed on the minute wheel 1. The hub of the crank lever 5 has a cylindrical surface 51 with a recess 52. L. A step wheel 9 having a special toothing comprising 24 3,177,647. Patented Apr. 13, 1965 relatively long teeth 10 is pivoted in a bridge 8 connected to the work plate 7 in a manner not illustrated in the drawings. Each third tooth 11 of the step wheel 9 is shortened so that a gap is formed in the toothing, the cylindrical locking surface 51 of the crank hub being adapted to engage with little clearance between the flanges of two teeth 10 of full length adjacent a gap outside a shortened tooth 11. In this way the step wheel 9 is usually locked against undesired rotation. A locking wheel 12 having a substantially cylindrical outer locking surface with a recess 13 is fixed to the step wheel 9. By means of an intermediate gear 14 the step wheel 9 is in gearing connection with an advancing wheel 15 having the same number of teeth as the step wheel 9 so that the advacing wheel 15 is driven at the same speed as the step wheel 9 and the locking wheel 12 respectively. A resilient advancing or stepping lever or arm 16 is fixed on the wheel 15, this lever having an actuating surface 17 at its free end and an inclined surface 18 adjacent the free end. Wheels 14- and 15 and lever 16 are pivoted in the bridge 8 in a well known manner with as little friction as possible. The diameter, tooth number and tooth form of wheels 9 and 14 are so designed that these wheels are in continuous and uniform engagement so that any angular displacement of wheel 9 is exactly transmitted I to wheels 14 and 15.

The ring-shaped date indicator 19 has an inner trapezeshaped toothing, whereby adjacent edges 20 at the crests of the teeth 21 of the date indicator are so disposed relaoblong hole 26 of the bridge 8. By this spring the date indicator is locked against return movement from any one of its indicating positions.

In order to keep the friction as low as possible the date indicator 19 is supported by means of a downwardly and inwardly directed flange 22 on a narrow shoulder 23 of the work plate 7 as shown in FIG. 5 and is secured against axial displacement by means of screws 24. For inserting screws 24 the date indicator 19 has at least one opening 25.

FIG. 1 illustrates the advancing or stepping mechanism of the date indicator 19 at the beginning of an advancing movement. The driving pin 6 of crank lever 5 has just engaged a tooth 10 of wheel 9 so that the wheel 9 will be driven in clockwise direction upon further rotation of the crank lever 5 in anticlockwise direction, this rotating movement of the wheel 9 being no longer hindered by the locking surface 51 because the driven tooth of wheel 9 will enter into the recess 52. Also the next full tooth 10 of wheel 9 will enter into the recess 52 during the stepping movement of step wheel 9. The rotation of wheel 9 is transmitted to the locking wheel 12 to the advancing wheel 15 and the advancing lever 16. It will be clear from the drawing that the effective lever arm of the advancing lever 16 substantially exceeds the diameter of the locking wheel 12. Since the end surface 17 of the lever 16 already engages a rear tooth flange of the date indicator 19 when the stepping or advancing rotation of wheels 9 and 15 starts, the date indicator 19 is new advanced by the lever 16 in clockwise direction at a speed in the order of double the circumferential speedof the locking wheel 12. Therefore, the tooth 21 of the date indicator 19 located outside the left end of the recess of the'locking wheel 12 will now completely enter into the recess 13 before the cylindrical surface of the locking wheel 12 again engages this tooth so that the advancing movement is not hindered by the locking wheel. The said tooth of the date indicator will thus run at a higher speed through the recess 13 whereby all parts are so designed that the tooth will never engage a portion of the locking wheel during the advancing movement of the date indicator. At the end of the advancing movement, that is when the driving pin 6 is leaving the toothing of wheel 9 as shown in FIG. 2, the recess 13 has reached the position shown in FIG. 2, this position being shifted by an angle of 45- or by A; of a full rotation relatively to the position shown in FIG. 1. When the recess 13 is in its end position shown in FIG. 2 the tooth of the date indicator may freely leave the recess. As shown in FIG. 2 the advancing lever 16 has reached an end position wherein its end surface 17 has just left the flange of the tooth Zll previously engaged for transmission of the advancing movement, and the edge 2% of this tooth now engages the inclined surface 18 of the advancing lever 16. The advancing lever 16 as well as the spring 27 prevent a return motion of'the date indicator, while a forward rotation is prevented by the cylindrical surface of the locking wheel l2. When the driving pin 6 engages the toothing of wheel 9 at the end of another full rotation of the minute wheel 1, that is after a time interval of 3 hours, wheels 9 and 115 are again rotated by 45. During this further stepping rotation the inclined surface 18 of lever 16 slides along the edge 29 of the tooth 21 engaging it (FIG. 2), whereby the elastical lever 15 is slightly bent inwardly for passing at the side of the tooth of the 4. and having a substantially cylindrical portion engaging the toothing of the date indicator ring with little clearance, said locking wheel having a recess in its substantially cylindrical portion, said. recess unlocking the date indidate indicator which is now locked against further rotation. The cylindrical surface of the locking wheel 12 is now fully turned into one tooth gap of the toothing of the date indicator (position shown in FIG. 4) so that the date indicator is now again, fully locked against rotation in any direction by the locking wheel 12. a

As shown most clearly in FIG. 4 the toothing of wheel 9 and the path of driving pin 6 are so disposed that the wheel 9 is rotated exactly by three tooth divisions during each of its stepwise advancing movements. Since the wheel 9 has 24 teeth it executes a full rotation in 24 hours. Therefore the recess 13 will return into the position shown in FIG. 1 at the end of the seventh partial rotation of the locking wheel 12. For this position of the locking wheel 12 the date indicator is already free to rotate in its advancing direction. However, any such movement would be limited by the right-hand portion of recess 13 as shown in FIG. 1 so that the advancing movement of the date indicator would be completed during the next stepwise rotation of the wheels 9 and 15 Without any possibility of losing the synchronism.

The synchronism cannot be distributed by uncontrolled rotation of the step wheel 9 and the parts mechanically coupled therewith when the driving pin 6 is disengaged from'the toothing of wheel 9, because the cylindrical surface 531 engaging a gap of wheel 9 prevents any rotation of this wheel between the stepping displacements thereof. When the recess 52 enters into the toothing of wheel 9 as shown in FIGS. 1 and 4 no rotation of wheel 9 is possible to such an extent that the synchronism may be disturbed until pin 6 completely enters into the toothing. The same conditions apply when the pin 6 leaves the toothing of wheel 9.

As mentioned above, the particular advantages of this invention reside in the small turning moment required for advancing the date indicator and the impossibility of losing the synohronism between the date indicator and the hour and minute hands of the timepiece.

What I claim is:

1. A timepiece having a toothed date indicator ring, comprising a rotatable resilient advancing lever adapted for engaging and advancing the date indicator ring, a rotatable locking wheel coupled with said advancing lever cator ring and allowing advance thereof when engaging intermittently rotating by a predetermined part of a full rotation said locking wheel and advancing lever, said recess and advancing lever engaging the toothing of the date indicator ring during one of said intermittent rotat ing movements for unlocking and advancing respectively the date indicator ring whereby the advancing lever assumes a predetermined end position at the end of its advancing movement, an inclined surface on the said advancing lever engaging a tooth of the date indicator ring when the advancing lever is in its said end position, and the advancing lever being elastically deformed for passage at the side of the said tooth of the date indicator ring by interaction of the tooth with the inclined surface when the advancinglever is further advanced from its said end position during the next step ofthe advancing means.

2. A timepiece according to'claim 1, wherein the date indicator comprises a trapeze toothing, the locking wheel engaging with little clearance between adjacent edges of the crest of neighbouring teeth.

3. A timepiece comprising a toothed date indicator, rotatable advancing means for the date indicator and locking means for the date indicator including a locking wheel rotatable with the same speed as the said advancing means and engaging the toothing of the date indicator, and locking means for locking said locking wheel against rotation between the periods of stepwise advance of th locking wheel and advancing means respectively, a stepping wheel for driving the locking wheel and advancing means respectively, said stepping wheel having shortened teeth at regularly spaced intervals between teeth of full length, and rotatable driving means for the stepping wheel having a substantially cylindrical locking portion with a recess, said locking portion engaging the toothing of the stepping wheel. I

4. A timepiece according to claim 3, wherein the stepping wheel gears with a transmisison wheel, the toothing of the stepping wheel and of the transmission wheel being so designed that continuous and regular engagement of such wheels is obtained in spite of the shortened teet of the stepping wheel.

5. A timepiece according to claim 3, each third tooth of the stepping Wheel being shortened.

6. A timepiece according to claim 5, wherein the'stepping wheel has 24 teeth. a f

7. A timepiece comprising a toothed date indicator ring, firstpivot means inside said date indicator ring, advancing means for the date indicator ring rotatably mounted on saidfirst pivot means, second pivot'means inside said date indicator ring and spaced from said first pivot means in the circumferential direction of the date indicator ring, a locking Wheel rotatably mountedon said second pivot means, said locking wheel having a substantially cylindrical portion with a recess in its cylindrical surface, the said date indicator ring, advancing means and substantially cylindricalport ion of the locking wheel disposed in a common plane whereby the said substantially cylindrical means for the said advancing means and locking wheel respectively.

8. A timepiece comprising a toothed date indicator ring, rotatable advancing means for the said date indicator ring intermittently operative for stepwise advance of the'date indicator ring, a locking wheel adapted for synchronous rotation together with the advancing means, driving means for rotatingthe said advancing means and locking wheel, said locking wheel having a substantially cylindrical portion engaging with little clearance the toothing of the date indicator ring for usually locking the date indicator ring against displacement, a recess in the substantially cylindrical portion of the locking wheel allowing displacement of the date indicating ring when engaging the toothing thereof, the locking wheel comprising a toothed driven wheel coupled with said substantially cylindrical locking portion and with said advancing means respectively, a driving member for said driven wheel for intermittently advancing said driven wheel, said driving member comprising a second substantially cylindrical portion having a recess, said second substantially cylindrical portion engaging with little clearance the References Cited by the Examiner UNITED STATES PATENTS 894,506 7/08 Johnson 235139 FOREIGN PATENTS 3 14,707 6/56 Switzerland.

toothing of said driven wheel thereby usually opposing 15 LEO SMILOW, Primary Examiner- 

1. A TIMEPIECE HAVING A TOOTHED DATE INDICATOR RING, COMPRISING A ROTATABLE RESILIENT ADVANCING LEVER ADAPTED FOR ENGAGING AND ADVANCING THE DATE INDICATOR RING, A ROTATABLE LOCKING WHEEL COUPLED WITH SAID ADVANCING LEVER AND HAVING A SUBSTANTIALLY CYLINDRICAL PORTION ENGAGING THE TOOTHING OF THE DATE INDICATOR RING WITH LITTLE CLEARANCE, SAID LOCKING WHEEL HAVING A RECESS IN ITS SUBSTANTIALLY CYLINDRICAL PORTION, SAID RECESS UNLOCKING THE DATE INDICATOR RING AND ALLOWING ADVANCE THEREOF WHEN ENGAGING THE TOOTHING OF THE DATE INDICATOR RING, DRIVING MEANS FOR INTERMITTENTLY ROTATING BY A PREDETERMINED PART OF A FULL ROTATION SAID LOCKING WHEEL AND ADVANCING LEVER, SAID RECESS AND ADVANCING LEVER ENGAGING THE TOOTHING OF THE 